2026-04-30 · By the Auto Trends technicians
The 6.7 Power Stroke (sometimes called the “Scorpion” because of its forward-facing intake) replaced the troubled 6.4 in 2011 and has been the backbone of the Ford F-Series Super Duty ever since. Compared to the 6.0 and 6.4 it succeeded, the 6.7 is a leap forward in reliability — but no engine is failure-free, and a 2011-era 6.7 with 150,000+ miles on the clock is going to need attention in some specific places.
This post is the failure-mode field guide we wish every 6.7 owner had before bringing the truck in. It’s based on the trucks we see at Auto Trends — service trucks, ranch rigs, ski-trip tow rigs, and daily-driver F-250s with everything from 60,000 to 280,000 miles on them.
The factory EGR cooler on the 6.7 is the first thing to fail on most high-mileage trucks. Symptoms include: white steam from the exhaust on warm-up, slow coolant loss with no visible leak, codes P040D / P040E, and in late stages, milky oil if coolant has crossed into the engine.
The fix isn’t “delete the EGR” (we don’t do that — federal Clean Air Act, and you’ll fail emissions inspection in any state that has one). The fix is replacing the cooler with an updated OEM unit. Some shops offer aftermarket high-flow units; we generally recommend OE because the failure mode is heat cycling, not flow restriction.
Cost varies by year and what else needs to come off to access it; typical range is $1,400–$2,400 with OEM Ford parts. We always quote in writing after inspection.
This is the one that owners lose sleep over. The Bosch CP4.2 high-pressure fuel pump in 2011–2019 6.7 PSDs has a documented failure mode: roller followers run dry, contact the camshaft, and explode. When that happens, metal debris contaminates the entire fuel system — injectors, rails, lines, the tank.
If the pump goes catastrophic on the road, the repair bill can reach $10,000–$15,000 because every fuel-touching component has to be cleaned or replaced. We’ve done the cleanup. It’s not pretty.
What we recommend: on high-mileage trucks (especially 2011–2014), consider proactive replacement before failure. We use OEM Bosch replacement pumps. We do not perform CP4-to-CP3 conversions because that involves bypassing emissions sensors that the ECM watches for — it’s a federal compliance issue.
What you can do today: use quality fuel, never run the tank dry, and change the fuel filter on schedule. Cheap fuel and contaminated fuel are the two main triggers we see for early CP4 failures.
The variable-geometry turbo on the 6.7 has an electronic actuator that gets sticky over time, especially on trucks that see a lot of heavy towing. Symptoms include: loss of boost, hesitation under acceleration, code P003A, or in extreme cases a check-engine light with limp mode.
Sometimes the fix is just cleaning soot off the actuator and recalibrating with the IDS scan tool. Sometimes the actuator itself needs replacement. Rarely the whole turbo (~$3,500 with OEM) is needed — but we always diagnose the actuator first because it’s a fraction of the cost.
The 6.7 has two NOx sensors (upstream and downstream of the SCR catalyst). They fail. When they do, you’ll see codes P229F, P2BAD, P207F — sometimes accompanied by a “Service DEF System” warning and a forced reduction in power output (“DEF derate”).
Replacement is straightforward but the parts aren’t cheap (~$300–$450 each, OEM). On 200,000+ mile trucks, replacing both NOx sensors plus a DEF tank header overhaul is common preventive work.
One thing we won’t do: delete the SCR or DEF system. We replace failed parts with OEM and recalibrate. The truck stays emissions-legal.
For all the failure modes above, this engine is fundamentally well-designed. The block, heads, and rotating assembly are robust enough to handle 300,000+ miles with disciplined service. We see 6.7 PSDs at 250,000 miles that run cleaner than a 50,000-mile aftermarket-tuned truck.
If you treat the 6.7 with the maintenance it deserves — quality oil at 7,500-mile intervals, fuel filter every 15,000–20,000, DEF fluid topped off, EGR cooler addressed proactively past 120,000 — it’ll be the cheapest truck per mile you’ve ever owned.
With disciplined maintenance, 250,000–300,000 miles is realistic. We’ve seen trucks past 350,000 still running strong. Failures are usually traceable to neglected oil changes, fuel quality issues, or unaddressed EGR/CP4 warnings.
Yes — but get a pre-purchase inspection that includes a scan for stored emissions codes, a coolant pressure test, and a fuel-filter inspection. Trucks that have been deleted are a hard pass for us; trucks with a documented service history are excellent buys.
No. (1) It’s federally illegal and CO has been actively enforcing. (2) The fuel-economy gain is overstated — most modern 6.7s already make close-to-optimal MPG with the emissions intact. (3) A deleted truck loses serious resale value and can’t pass inspection in many states. We don’t perform deletes and we don’t service deleted trucks for emissions-affecting work.
Ford recommends 7,500 miles for normal duty and 5,000 for severe duty (towing, dust, cold). We split the difference at 5,000–7,500 depending on use. Always full synthetic, always meeting Ford spec WSS-M2C171-F1. Filter every change with an OEM Motorcraft filter.
Oil every 5,000–7,500. Fuel filter every 15,000–20,000. Air filter as needed (sooner if you’re in dust). DEF fluid as the gauge calls. Coolant flush at 100,000. Transmission fluid every 60,000 if towing, 100,000 otherwise. Diff fluids every 60,000 if towing.
If your vehicle is showing the symptoms in this post, the next step is a real diagnosis. Bring it in or book online.
Book a diagnosis →Most appointments available within 48 hours. Free estimate. Photo inspection. A real person who answers the phone.